An electro-optical shutter comprises an electro-optical crystal suitable for transmitting or blocking a light beam according to whether or not it is subjected to an electric field. Such a crystal which therefore operates on the Pockel (or Kerr) effect is associated with means which can transmit or interrupt the electric field.
Generally, the crystal is a niobate or a tantalate, while the previously mentioned means is a silicon switch which is made conductive by application of an optical signal.
However in known shutters, an impedance discontinuity is observed at the junction between the silicon and the crystal, this discontinuity being due to the difference between their dielectric constants. A deterioration of the electric signal and an appreciable loss of energy result therefrom.
Further it is observed that it is difficult to increase the dimensions of the electric crystal to make it compatible with the diameter of said light beam.
Preferred embodiments of the present invention remedy these drawbacks and provide a shutter which is suitable for operating reliably and without disturbance within the pico-second range and with high energy efficiency.